1. Field of the Art
The present invention relates to an ink cartridge for supplying ink to a recording head. The ink cartridge is mounted on a carriage in which a recording head for jetting ink droplets is attached.
2. Related Art
An ink jet recording apparatus prints images of photo-like quality with a relatively simple structure, so that it is widely used as a recording apparatus for personal use. In such a recording apparatus, recording heads for a black ink and color inks are generally mounted on a carriage, then cartridges for the black ink and the color inks are installed thereon, thereby the inks are supplied to each recording head via an ink supply needle.
In the case that most of the printing to be printed by the recording apparatus is composed of text data, the amount of the color inks to be used is little and the color inks are not frequently used, so that the frequency of an exchange of the color ink cartridge is much lower than that of the black ink cartridge. Accordingly, there is a problem that the effective date of the color ink cartridge expires before the consumption of all of the color inks, which requires the premature replacement of the color ink cartridge, thereby increasing the cost.
On the other hand, when a color printing is often conducted the black ink is not frequently used and the effective date may expire before consuming all of the ink in the black cartridge.
Moreover, when the recording apparatus itself is not used frequently, the effective date expires when the inks remain in both black and color ink cartridges.
In order to solve the above-mentioned problem, an ink cartridge may be produced by decreasing the volume of the ink cartridge. However, a gap is generated between the ink cartridge and a holder housing the ink cartridge, so that a distortion may be generated by the reciprocating carriage at a connecting portion between the ink supply needle and an ink supply port. Also, a new metallic mold is necessary, thereby increasing costs.
In order to solve those problems, as shown in Japanese published application no. 9-262988, a filler is inserted in the bottom of a container body composing an ink cartridge with a normal volume so as to decrease the amount of filled ink.
According to the reference, just filling the filler in the container body makes the amount of the filled ink decrease without changing a shape of the container. However, a shape adjacent to an ink supply port is changed, which greatly affects the outflow characteristics of ink to the recording head. Therefore, the printing characteristics may be fluctuated.
It is an object of the present invention to provide an ink cartridge with a small volume, which has the same characteristics of ink discharge as those of an ink cartridge with a normal volume.
It is another object of the present invention to provide a small volume ink cartridge by using the same container body of an ink cartridge with a normal volume.
It is another object of the present invention to provide an ink cartridge for use in an ink jet recording apparatus for minimizing the amount of stored ink without causing any difficulties attaching to and removing from a carriage.
It is another object of the present invention to provide an ink cartridge for use in an ink jet recording apparatus without wasting material, or without using any spacer and so on.